Some applications in automotive lighting or other applications involve a plurality of LED chains, each including a number of LEDs connected in series. The number may vary depending on the specific application. One or more of the LEDs can be bypassed at times, temporarily reducing the length of the LED chain. A DC/DC converter may control the current flowing through the LED chain as different numbers of the LEDs in the chain are used, while the output voltage is set by the number and the forward voltage of the LEDs that compose the chain.